CHAPTER XIX 



CUCURBITACEAE 



CUCURBIT A spp. 



THE gourd family, Cucurbitaceae, is widely distributed and 

 includes approximately 90 genera, most of which are tropical 

 or subtropical, although a few forms occur in the native flora of 

 the colder portions of the temperate zone. Three genera are 

 cultivated for their edible fruits: CitruUus, the watermelon; 

 Cucumis, the cucumber and melons; and Cucurbita, which includes 

 pumpkins, squashes, and gourds. In the genus Cucurbita three 

 species are extensively grown, C. Pepo L., C. maxima Duchesne, 

 and C. moschata Duchesne, commercial varieties of the first two 

 being the most generally used. Under cultivation the three 

 species grow as annuals; and, although sensitive to frost, they 

 develop with such rapidity that some varieties are grown in the 

 northern states. 



GENERAL MORPHOLOGY 



The Root. — The root system is characterized by a strong tap 

 root which, according to Weaver and Bruner (39), may penetrate 

 to a depth of 6 feet at maturity although branching is not extensive 

 below the two-foot level. The branches spread widely, occupying 

 a radius of nearly zo feet, and the main laterals have numerous 

 secondary branches i to 8 feet long which in turn branch until 

 there is a remarkable network of rootlets that completely occupies 

 the soil near the surface. In addition to the primary root system, 

 the adventitious or nodal roots may attain a length of 4 to 5 feet, 

 and they also branch so that the absorbing area is much increased. 



The Shoot. — In general, the plants have prostrate vine-like 

 stems, but some varieties of C. Pepo are more or less bushy and 

 semi-erect. In the latter, the internodes are much shortened, as 

 compared with the trailing types, and tendrils are absent. In 

 the prostrate forms, three to several lateral branches arise from 

 nodes near the base of the stem axis; and extend outward for 



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